NED Abstract

Copyright by American Astronomical Society.
Reproduced by permission
2002AJ....124.2440S
THE THREE-DIMENSIONAL STRUCTURE OF THE VIRGO CLUSTER REGION FROM
TULLY-FISHER AND H I DATA
JOSE M. SOLANES
Departament d'Enginyeria Informatica i Matematiques, Campus Sescelades,
Universitat Rovira i Virgili, Avenida Paisos Catalans 26,
E-43007 Tarragona, Spain; jsolanes@etse.urv.es
TERESA SANCHIS AND EDUARD SALVADOR-SOLE
Departament d'Astronomia i Meteorologia and CER d'Astrofisica, Fisica de
Particules i Cosmologia, Universitat de Barcelona, Avenida Diagonal 647,
E-08028 Barcelona, Spain; tsanchis@am.ub.es, eduard@am.ub.es
AND
RICCARDO GIOVANELLI AND MARTHA P. HAYNES
Center for Radiophysics and Space Research and National Astronomy and
Ionosphere Center, 104 Space Sciences Building,1 Cornell University,
Ithaca, NY 14853-6801; riccardo@astro.cornell.edu, haynes@astro.cornell.edu
Received 2002 May 22; accepted 2002 August 6
ABSTRACT
The distances and H I contents of 161 spiral galaxies in the region of
the Virgo cluster are used to gain insight into the complicated structure
of this galaxy system. Special attention has been paid to the investigation
of the suggestion presented in an earlier work that some peripheral Virgo
groups may contain strongly gas-deficient spiral galaxies. The
three-dimensional galaxy distribution has been inferred from quality
distance estimates obtained by averaging distance moduli based on the
Tully-Fisher relationship taken from eight published data sets previously
homogenized, resulting in a relation with a dispersion of 0.41 mag.
Previous findings that the spiral distribution is substantially more
elongated along the line of sight than in the plane of the sky are
confirmed by the current data. In addition, an important east-west
disparity in this effect has been detected. The overall width-to-depth
ratio of the Virgo cluster region is about 1 : 4, with the most distant
objects concentrated in the western half. The filamentary structure of the
spiral population and its orientation are also reflected by the
H I-deficient objects alone. The H I deficiency pattern shows a central
enhancement extending from ~16 to 22 Mpc in line-of-sight distance; most of
this enhancement arises from galaxies that belong to the Virgo cluster
proper. However, significant gas deficiencies are also detected outside the
main body of the cluster in a probable group of galaxies at line-of-sight
distances ~25-30 Mpc, lying in the region dominated by the southern edge of
the M49 subcluster and clouds W' and W, as well as in various foreground
galaxies. In the Virgo region, the H I content of the galaxies then is not
a straightforward indicator of cluster membership.
Key words: galaxies: clusters: individual (Virgo) - galaxies: evolution -
galaxies: ISM - galaxies: spiral - methods: data analysis